Repeated batch operation using two fermentors (RBTF) to penicillin fermentation was demonstrated by computer simulation to improve productivity. Three operation modes were compared: chemostat, repeated batch operation using a single fermentor (RBSF) and RBTF; in each case account was made of the lag period before growth. The simulated fermentor performances were assessed on the basis of the penicillin productivity and concentration; the simulation was based on published batch fermentation data. It was shown that RBTF was superior to RBSF and chemostat. The advantage of RBTF increased as the lag period became greater. 相似文献
The Earth Simulator (ES), developed under the Japanese government’s initiative “Earth Simulator project”, is a highly parallel vector supercomputer system. In this paper, an overview of ES, its architectural features, hardware technology and the result of performance evaluation are described.
In May 2002, the ES was acknowledged to be the most powerful computer in the world: 35.86 teraflop/s for the LINPACK HPC benchmark and 26.58 teraflop/s for an atmospheric general circulation code (AFES). Such a remarkable performance may be attributed to the following three architectural features; vector processor, shared-memory and high-bandwidth non-blocking interconnection crossbar network.
The ES consists of 640 processor nodes (PN) and an interconnection network (IN), which are housed in 320 PN cabinets and 65 IN cabinets. The ES is installed in a specially designed building, 65 m long, 50 m wide and 17 m high. In order to accomplish this advanced system, many kinds of hardware technologies have been developed, such as a high-density and high-frequency LSI, a high-frequency signal transmission, a high-density packaging, and a high-efficiency cooling and power supply system with low noise so as to reduce whole volume of the ES and total power consumption.
For highly parallel processing, a special synchronization means connecting all nodes, Global Barrier Counter (GBC), has been introduced. 相似文献
The Co/MFI(SiO2/Al2O3 = 30) were prepared by a precipitation method with NaOCl in alkali solutions exhibited high activities to N2 at 250 °C for the selective catalytic reduction (SCR) of NOx. These catalysts showed two UV–vis bands at 700 and 400 nm, indicating the presence of octahedral Co(III) as well as tetrahedral Co(II). The high SCR activity over such Co(III, II)/MFI(30) seems to come from Co(III)---O moieties. The Co(II)MFI(30) catalysts prepared from Co(II)Cl2 exhibited low SCR activities due to the presence of tetrahedral Co(II) ions in MFI. Less CO formation occurred over Co/MFI catalysts. The Fe/MFI(30) catalyst exhibited high activity due to the presence of some Fe---O species in MFI but more amount of CO were produced during SCR. H/MFI(30) catalyst exhibited a good SCR activity. However, more amount of carbonaceous deposits were produced on it. The correlation between acid concentration and SCR activity was discussed over H/MFIs. 相似文献
We previously reported that inostamycin, an inhibitor of CDP-DG: inositol transferase, inhibited cell proliferation in normal rat kidney (NRK) cells by blocking cell cycle progression at the G1 phase. In the present paper, we report the effect of inostamycin on the serum-induced activation of Ser/Thr protein kinases that are involved in G1 progression. In quiescent NRK cells mitogen-activated protein kinase (MAP kinase) and casein kinase II were activated within 15 min after serum addition. Neither activation was affected by the treatment with inostamycin. However, in the inostamycin-treated cell, cyclin-dependent kinase 2 (CDK2) failed to be activated after serum stimulation. Since serum-induced expression of cyclin E was also suppressed by inostamycin, this inhibitor would appear to block CDK2 activation by inhibiting cyclin E expression. Furthermore, inostamycin also inhibited cyclin D1 expression induced by serum; and consequently, hyperphosphorylation of retinoblastoma protein (pRB) by RB-kinases such as CDK4 and CDK2 was abolished, which would result in elimination of functional inactivation of pRB. Thus, early G1 arrest in NRK cells by inostamycin is due to the inhibition of cyclin D1 and E expressions. 相似文献
We investigated Au catalysts supported on TiO2, Fe2O3, and ZnO for their preferential oxidation of CO in a H2-rich atmosphere. Both full conversion and selectivity were achieved over Au/Fe2O3 and Au/ZnO around room temperature, but at higher temperatures the CO conversion was suppressed due to competition between CO and H2. 相似文献
Subarachnoid haemorrhage (SAH) often leads to subarachnoid fibrosis and resultant normal pressure hydrocephalus; however, how subarachnoid fibrosis occurs is unknown. We examined the changes within arachnoid granulations (AGs) and the subarachnoid space (SAS) chronologically at the parasagittal region obtained from patients with SAH at autopsy and made comparison with controls by immunostaining for cytokeratin, specific marker for leptomeningeal cells and by the elastica Masson-Goldner methods. Within a week some AGs were torn, and many inflammatory cells filled the AGs and SAS. Cytokeratin positive cells were scarce. During the next two weeks cytokeratin positive cells increased. After three weeks, AGs and SAS were filled by dense deposits of extracellular matrices surrounded by multiple layers of leptomeningeal cells. 相似文献
SiB4±x and SiB6 plates were prepared by chemical vapour deposition (CVD) using SiCl4, B2H6 and H2 gases under the conditions of deposition temperatures (Tdep) from 1323–1773 K, total gas pressures (Ptot) from 4–40 kPa and B/Si source gas ratio (mB/Si=2B2H6/SiCl4) from 0.2–2.8. The effects of CVD conditions on the morphology, structure and composition of the deposits were examined.
High-purity and high-density SiB4±x and SiB6 plates about 1 mm thick were obtained at the deposition rates of 71 and 47 nm s−1, respectively. The lattice parameter, composition and density of CVD SiB4±x plates were dependent on their non-stoichiometry. The lattice parameter,a, was 0.6325 nm, butc ranged from 1.262–1.271 nm.The B/Si atomic ratio ranged from 3.1–5.0, and the density ranged from 2.39–2.45×103 kg m−3. The CVD SiB6 plates showed constant values of lattice parameters (a=1.444 nm,b=1.828 nm,c=0.9915 nm), composition (B/Si=6.0) and density (2.42×103 kg m−3), independent of CVD conditions. 相似文献
To achieve higher fatigue resistance against subsurface crack generation, both the refinement of grain structure and the introduction
of mobile dislocations on various slip systems have been shown to be effective in the 32Mn-7Cr austenitic steel. A novel treatment
which consisted of cold grooved rolling and partial recrystallization was introduced to modify the microstructure. High-cycle
fatigue properties and fatigue-crack generation were investigated for both the solution-treated (ST) and the partially recrystallized
(PR) materials at 77 K. The PR material displayed higher fatigue strength than the ST material, especially in the high-cycle
regime. No subsurface crack generation was detected for the PR material; however, it appeared in the lower peak stress and/or
in the longer-life range for the ST material. Intergranular facets formed a subsurface crack initiation site in the ST material.
Since the dislocation structure that developed in the fatigued PR material assisted homogeneous and multidirectional plastic
deformation, the localized deformation and/or the stress concentration at the grain boundaries by coplanar arrays were believed
to be relieved. Therefore, intergranular cracking due to incompatibility at a grain boundary may disappear. 相似文献
Summary The rate constants for intramolecular excimer formation, kDM, of poly(α-methylstyrene) with different molecular weight were determined by using picosecond pulse radiolysis. Values of
kDM for poly(α-methylstyrene) are a little smaller than those for polystyrene with nearly same molecular weight. It appears to
be mainly due to steric hindrance by methyl substituent of main chain. 相似文献